Intravascular diseases are commonly treated by relatively non-invasive techniques, such as percutaneous transluminal coronary angioplasty (PTCA). PTCA is well known in the art and typically involves the use of a guide catheter, a guide wire and a balloon catheter, possibly in combination with other intravascular devices. A typical balloon catheter has an elongate shaft with a balloon attached proximate its distal end, and an inflation manifold attached proximate the proximal end. In use, the balloon catheter is advanced through a lumen in the guide catheter over the guide wire such that the balloon is positioned adjacent a restriction in a diseased vessel. The balloon is then inflated and the restriction in the vessel is opened.
One type of balloon catheter design is an over-the-wire type balloon catheter. An over-the-wire catheter typically includes a lumen extending therethrough adapted to receive a guide wire. Once a guide wire has been placed within a patient's vascular system, the over-the-wire type balloon catheter may be back-loaded onto the guide wire and advanced, tracking the guide wire, along the tortuous passages of a patient's vascular system until the balloon located at the distal end of the over-the-wire catheter is positioned across the stenosis.
The over-the-wire type intravascular catheter can be exchanged for a second balloon catheter without removing the guide wire. This allows an exchange of catheters without having to repeat the difficult and time consuming task of positioning the guide wire across a stenosis. In order to maintain the position of the guide wire within the patient's vascular system, a physician must hold onto a proximal end portion of the guide wire during the exchange procedure. To facilitate such an exchange procedure, a guide wire having a sufficiently long length (e.g., 300 cm) or a guide wire extension must be used such that the entire balloon catheter can be completely withdrawn over the guide wire, while maintaining position of the guide wire. The main disadvantage of this method is the length of the guide wire extending outside of the patient's body must be longer than the length of the balloon catheter being exchanged.
A variation of the over-the-wire balloon catheter which does not require such a long guide wire to facilitate the exchange of a first catheter with a second catheter is a balloon catheter having a single operator exchange type construction. A single operator exchange balloon catheter has at least one lumen extending over substantially the entire length of the catheter and a second shorter guide wire lumen. The second shorter guide wire lumen typically begins at a location close to a distal portion of the catheter, usually proximal of the balloon, and extends distally through the balloon and out an opening at the distal end of the balloon. With a single operator exchange type catheter, in order to maintain the position of the guide wire, it is only necessary that the length of the guide wire extending from the patient's body be longer than the length of the second guide wire lumen to facilitate an exchange procedure.
With the above described over-the-wire and single operator exchange type balloon catheters, a physician must still be able to handle the length of the balloon catheter removed from the patient's vascular system during exchange of a first catheter with a second catheter. A typical balloon catheter often exceeds 110 cm in length. It is often cumbersome for a physician and an attending assistant to maintain control of the length of the balloon catheter in exchanging a first balloon catheter for a second balloon catheter while holding the guide wire to maintain position of the guide wire across the stenosis.
Further, a PTCA procedure may be performed in either (or both) a proximal or distal portion of each of the coronary arteries, each requiring a different sized balloon catheter. There are anatomical differences between patients which may require a different shaped or different sized intravascular device for treatment.
To meet the above cited needs, balloon catheters are manufactured in various sizes and shapes as a total unit which is used once and discarded. However, often only a portion of each device is of different size or shape. For example, only the distal portion of a balloon catheter varies in shape and size depending on the given anatomical geometry to be navigated and the location of the stenosis receiving treatment, while the proximal portion of the balloon catheter is of the same size and is almost always a straight tubular member.
Accordingly, it is desirable to have a single operator exchange type balloon catheter which allows the use of a relatively short length of guide wire extending outside of the patient's body during a catheter procedure. It is desirable to have a catheter assembly which facilitates balloon catheter exchanges, wherein a distal portion of the balloon catheter may be changed to a different size as necessitated by the catheter procedure for use with a standard balloon catheter proximal portion. Further, it would be desirable to have a catheter management system which maintains organized control of the standardized proximal portion of the balloon catheter during exchange of an interchangeable distal portion in a balloon catheter exchange procedure.